Going to great lengths
With pressure on the sea floor too great for human divers, the Perdido engineering team used remote-controlled submarine robots to perform the difficult task of connecting the new and existing pipelines.
Controlled from the surface, these 300-hp remotely-operated vehicles (ROVs) supplied by Oceaneering International can reach depths of over 3,000 metres (10,000 feet). They are about the size of a large car. Yet their articulated arms can handle delicate tasks such as turning valves and programming control panels. Their video and lighting systems provided a clear view of the action; operators often used them in tandem, positioning one to provide an alternative viewing angle while the other manipulated tools or performed other tasks.
The first task was to make the operation safe. After closing the existing pipeline, they installed a clamp to seal the pipe instantly if anything went wrong as they cut into it. They also installed pumps and an undersea storage system to capture any leakage. A containment dome capped the working area as a further precaution.
It took two and a half years of designing, planning and training to reach the point where the connection work could begin. The patience and attention to detail paid off. When the robots carried out the operation, not a single drop of oil leaked from the pipe.
As the remotely-operated machines descended into the darkness, they encountered rarely seen sea creatures such as the magnapinna big fin squid. Most cephalopods have eight short arms and two long tentacles. This species, caught on camera at 2km (1.24 miles) beneath the surface, had ten tentacles of the same length dangling from elbow-like joints. An undulating fin looked like an alien’s head.
The squid appeared to have appendages 5-10 metres (16-33 feet) long. Despite its size, the species’ existence had been unknown until then. Perdido’s pipeline had to be routed to avoid disturbing other deep-sea inhabitants. These included a chemosynthetic colony-pale crabs and other bizarre creatures that feed on oil seeping naturally from the sea floor.
Marine biologists involved in deep-sea research now commonly work with Shell to access its technically-advanced equipment and video footage.